Fix issue where DELETE always returns 1 when using FLASH

Former-commit-id: 0574db59fdc740255388ae77d2ece8622898bb49

src/IStorage.h

@@ -22,7 +22,7 @@ public:
     virtual void retrieve(const char *key, size_t cchKey, callbackSingle fn) const = 0;
     virtual size_t clear() = 0;
     virtual bool enumerate(callback fn) const = 0;
-    virtual size_t count() const = 0;
+    virtual size_t count(bool fStrict) const = 0;
 
     virtual void beginWriteBatch() {} // NOP
     virtual void endWriteBatch() {} // NOP

src/db.cpp

@@ -2195,7 +2195,7 @@ dict_iter redisDbPersistentData::random()
 size_t redisDbPersistentData::size() const 
 { 
     if (m_spstorage != nullptr)
-        return m_spstorage->count();
+        return m_spstorage->count(false);
     
     return dictSize(m_pdict) 
         + (m_pdbSnapshot ? (m_pdbSnapshot->size() - dictSize(m_pdictTombstone)) : 0); 

src/storage/rocksdb.cpp

@@ -24,9 +24,16 @@ bool RocksDBStorageProvider::erase(const char *key, size_t cchKey)
 {
     rocksdb::Status status;
     if (m_spbatch != nullptr)
+    {
         status = m_spbatch->Delete(m_spcolfamily.get(), rocksdb::Slice(key, cchKey));
+    }
     else
+    {
+        std::string strT;
+        if (!m_spdb->KeyMayExist(ReadOptions(), m_spcolfamily.get(), rocksdb::Slice(key, cchKey), &strT))
+            return false;
         status = m_spdb->Delete(WriteOptions(), m_spcolfamily.get(), rocksdb::Slice(key, cchKey));
+    }
     return status.ok();
 }
 
@@ -40,7 +47,7 @@ void RocksDBStorageProvider::retrieve(const char *key, size_t cchKey, callbackSi
 
 size_t RocksDBStorageProvider::clear()
 {
-    size_t celem = count();
+    size_t celem = count(false);
     auto status = m_spdb->DropColumnFamily(m_spcolfamily.get());
     auto strName = m_spcolfamily->GetName();
 
@@ -53,7 +60,18 @@ size_t RocksDBStorageProvider::clear()
     return celem;
 }
 
-size_t RocksDBStorageProvider::count() const
+size_t RocksDBStorageProvider::count(bool fStrict) const
+{
+    size_t count = 0;
+
+    if (fStrict)
+    {
+        std::unique_ptr<rocksdb::Iterator> it = std::unique_ptr<rocksdb::Iterator>(m_spdb->NewIterator(ReadOptions(), m_spcolfamily.get()));
+        for (it->SeekToFirst(); it->Valid(); it->Next()) {
+            ++count;
+        }
+    }
+    else
     {
         std::string strelem;
         if (!m_spdb->GetProperty(m_spcolfamily.get(), rocksdb::DB::Properties::kEstimateNumKeys, &strelem))
@@ -61,6 +79,7 @@ size_t RocksDBStorageProvider::count() const
         std::stringstream sstream(strelem);
         size_t count;
         sstream >> count;
+    }
     return count;
 }
 

src/storage/rocksdb.h

@@ -29,7 +29,7 @@ public:
 
     virtual void flush() override;
 
-    size_t count() const;
+    size_t count(bool fStrict) const;
 
 protected: